Validation of a newly generated oxytocin antibody for enzyme-linked immunosorbent assays.

The biological and psychological significance of oxytocin is increasingly recognized; however, reliable assays of oxytocin in biological samples have not been developed. We raised a new oxytocin polyclonal rabbit antibody against synthetic oxytocin. The affinity of antibodies to oxytocin was examined by a radio-immunoassay and compared with that of a previously validated antibody. One antibody showed affinity for oxytocin in the radio-immunoassay. We developed a solid-phase ELISA for oxytocin using this antibody and compared it with existing methods. The newly developed ELISA showed comparable results using urine samples but not using serum samples. These results indicate that the new ELISA is useful for urinary oxytocin; further modifications, such as different extraction methods, are needed for its application to serum oxytocin.